This invention relates generally to the decontamination of industrial wastewaters, and particularly to the treatment of oil refinery wastewaters and concentrated, oily, industrial wastewaters not amenable to conventional secondary treatment due to the presence of refractory or toxic organic, metallic, and organometallic chemical compounds.
The processing of oil-shale and similar substances creates the need either to treat and dispose of wastewaters contaminated during the on-site processing or to treat these wastewaters for reuse. However, before such wastewaters can be effectively disposed or reused, certain environmental problems, such as possible water pollution and air pollution, toxicity, nonbiodegradeability, biofouling, scaling, and corrosion need to be solved. Numerous approaches have been proposed to meet these demands, including steam stripping, oil and grease removal, adsorption, biological oxidation, reverse osmosis, chemical oxidation, flocculation and sedimentation, filtration, activated sludge treatment, final clarification, and ammonia steam stripping. To date, no cost effective treatment has been found for oil shale retort water and certain petroleum wastewaters which are both highly concentrated and highly toxic.
Open-celled polyurethane foam filters are just beginning to be commercialized in the United States for water and wastewater treatment, although they have been utilized for air pollution control for some years. A polyurethane foam filtration system using a cationic polymer additive has been investigated in pilot plants by Union Carbide Corporation.
The Toyo Rubber Industry Company, Ltd. of Japan manufactures polyurethane foams suitable for filtration processes. Japanese patent 7842,450, issued Apr. 17, 1978, to S. Fukushima, S. Yoshimura, T. Nagai, H. Nodo, and K. Fujita, discloses a method of manufacturing a polyurethane foam for use in a filtration process, while Japanese patent 7898,155, issued Aug. 28, 1978, to S. Yoshimura, S. Fukushima, T. Nagai and K. Fujita, discloses a wastewater treatment process employing a polyurethane foam filter. The treatment process described in the latter uses CaC1.sub.2 treatment, skimming, and filtering through a packed tower containing sand, anthracite, or glass beads. The wastewater is then passed through a stationary, ionized, polyurethane-filled tower as a subsequent step.
U.S Pat. No. 3,617,551, issued Nov. 2, 1971, to W. F. Johnston, discloses an apparatus useful for purifying oil contaminated water in which the water to be treated is passed through a chamber containing polyurethane foam for absorbing the oil. Periodically, the filter material is compressed so as to squeeze the absorbed oil from it.
U.S. Pat. No. 4,279,757, issued July 21, 1981, to G. Debeuckelaer, et al., discloses a process for separating hydrophobic organic liquids from water which comprises passing a mixture of water and organic liquids through a column-like vessel which is filled with polyurethane foams having densities of 15 to 200 grams per liter, and preferably in the range of 30 to 60 grams per liter.
U.S. Pat. No. 4,212,733, issued July 15, 1980, to Y. Goto, et al., discloses an oil-water separation filter employing sintered polyethylene powder bonded to a fibrous layer, while U.S. Pat. No. 4,237,237, issued Dec. 2, 1980, to W. Jarre et al, discloses the manufacture and use of hydrophobic polyurethane foams. U.S. Pat. No. 4,430,230, issued Feb. 7, 1984, to T. Satake, discloses a method for removal of impurities from liquid mixtures by kneading the impurities-containing liquid mixture with a viscoelastic material having an affinity with the impurities and having substantially no affinity for the liquid medium.
U.S. Pat. No. 4,238,326, issued Dec. 9, 1980, to B. A. Wolf, discloses a fluid processor apparatus and method, and more particularly a petrochemical fluid processing apparatus and method for removing elements such as water or moisture from a stream of fluid (liquid or gas) wherein an electric potential is applied to at least an anode electrode plate and a permanently magnetized cathode electrode plate. A reactor containing a polypropylene mesh material for contacting the fluid is used. The polypropylene mesh material has a hemispherical configuration conforming to the concave bottom of the shell, and an integrally formed center channel extending upward into the middle chamber, and is designed to coalesce water and moisture.